Not sure from which rubber you are coming. But ZGR in both cases means 56° sponge, which makes opening up against backspin not an easy shot. If you want to find out, how 56° feel, I would go with the cheaper Tronix ZGR (Rhyzen ZGR is discontinued) and if you can handle it and need more speed, go for Dynaryz.
If you want to go for a Dynaryz, I would suggest to start with ZGX. Softer sponge and a bit more forgiving in block and flat hit. If you then find out, that you still need more speed, go for the ZGR afterwards.